Print promotion rate and semi-space copy rate in --trace-gc-nvp.

src/heap.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HEAP_H_
 #define V8_HEAP_H_
 
 #include <cmath>
 
 #include "allocation.h"
@@ skipping 2586 matching lines @@
   // Sets the GC count.
   void set_gc_count(unsigned int count) { gc_count_ = count; }
 
   // Sets the full GC count.
   void set_full_gc_count(int count) { full_gc_count_ = count; }
 
   void increment_promoted_objects_size(int object_size) {
     promoted_objects_size_ += object_size;
   }
 
+  void increment_semi_space_copied_object_size(int object_size) {
+    semi_space_copied_object_size_ += object_size;
+  }
+
   void increment_nodes_died_in_new_space() {
     nodes_died_in_new_space_++;
   }
 
   void increment_nodes_copied_in_new_space() {
     nodes_copied_in_new_space_++;
   }
 
   void increment_nodes_promoted() {
     nodes_promoted_++;
@@ skipping 36 matching lines @@
   // collection and the end of the previous collection.
   intptr_t allocated_since_last_gc_;
 
   // Amount of time spent in mutator that is time elapsed between end of the
   // previous collection and the beginning of the current one.
   double spent_in_mutator_;
 
   // Size of objects promoted during the current collection.
   intptr_t promoted_objects_size_;
 
+  // Size of objects copied to the other semi-space during the current
+  // collection.
+  intptr_t semi_space_copied_object_size_;
+
   // Number of died nodes in the new space.
   int nodes_died_in_new_space_;
 
   // Number of copied nodes to the new space.
   int nodes_copied_in_new_space_;
 
   // Number of promoted nodes to the old space.
   int nodes_promoted_;
 
   // Incremental marking steps counters.
@@ skipping 145 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_